[Bug 185633] [pf] scrubbing bug in transparent mode bug with bigger than MTU UDP packet

[bugzilla-noreply at freebsd.org]

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=185633

Olivier Cochard <olivier at freebsd.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |olivier at freebsd.org

--- Comment #5 from Olivier Cochard <olivier at freebsd.org> ---
Let me restart my virtual-lab on -current (same version for all VMs):

root at VM2:~ # uname -a
FreeBSD  12.0-CURRENT FreeBSD 12.0-CURRENT #0 r304964M: Sun Aug 28 21:49:48
CEST 2016    
olivier at lame4.bsdrp.net:/usr/obj/BSDRP12.amd64/usr/local/BSDRP/BSDRP12/FreeBSD/src/sys/amd64
 amd64

Simple lab diagram:

VM 1 (vtnet0)------(vtnet0) VM2 (vtnet1) -------- (vtnet1) VM 3

VM1 setup:
sysrc ifconfig_vtnet0="inet 10.0.0.1/24"
service netif restart

VM 2 setup:
sysrc ifconfig_vtnet0="up"
sysrc ifconfig_vtnet1="up"
sysrc cloned_interfaces="bridge0"
sysrc ifconfig_bridge0="addm vtnet0 addm vtnet1 up"
sysrc pf_enable=yes
cat > /etc/pf.conf <<EOF
set skip on lo0
scrub
pass
EOF
service netif restart
service pf start

VM 3 setup:
sysrc ifconfig_vtnet1="inet 10.0.0.3/24"
service netif restart

Now a standard ping works but not fragmented (same problem with UDP).
Example from VM1 to VM3:

root at VM1:~ # ping -c 1 10.0.0.3
PING 10.0.0.3 (10.0.0.3): 56 data bytes
64 bytes from 10.0.0.3: icmp_seq=0 ttl=64 time=0.258 ms

--- 10.0.0.3 ping statistics ---
1 packets transmitted, 1 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.258/0.258/0.258/0.000 ms

=> Works with "standard size" (non-fragmented) ICMP ping.

root@:~ # ping -c 1 -s 1500 10.0.0.3
PING 10.0.0.3 (10.0.0.3): 1500 data bytes

--- 10.0.0.3 ping statistics ---
1 packets transmitted, 0 packets received, 100.0% packet loss

=> But not with fragmented ICMP

A tcpdump on VM2 or VM3 give the same "corrupted" IP packet generated:

root at VM2:~ # tcpdump -vv -pnei vtnet1
tcpdump: listening on vtnet1, link-type EN10MB (Ethernet), capture size 262144
bytes
09:39:59.656215 20:00:40:01:33:fa > 45:00:05:dc:0d:24, ethertype Unknown
(0x0a00), length 1500:
        0x0000:  0001 0a00 0003 0800 12d1 b907 0000 57c4  ..............W.
        0x0010:  02ef 000a 16c8 0809 0a0b 0c0d 0e0f 1011  ................
        0x0020:  1213 1415 1617 1819 1a1b 1c1d 1e1f 2021  ...............!
        0x0030:  2223 2425 2627 2829 2a2b 2c2d 2e2f 3031  "#$%&'()*+,-./01
        0x0040:  3233 3435 3637 3839 3a3b 3c3d 3e3f 4041  23456789:;<=>?@A
        0x0050:  4243 4445 4647 4849 4a4b 4c4d 4e4f 5051  BCDEFGHIJKLMNOPQ
        0x0060:  5253 5455 5657 5859 5a5b 5c5d 5e5f 6061  RSTUVWXYZ[\]^_`a
        0x0070:  6263 6465 6667 6869 6a6b 6c6d 6e6f 7071  bcdefghijklmnopq
        0x0080:  7273 7475 7677 7879 7a7b 7c7d 7e7f 8081  rstuvwxyz{|}~...
        0x0090:  8283 8485 8687 8889 8a8b 8c8d 8e8f 9091  ................
        0x00a0:  9293 9495 9697 9899 9a9b 9c9d 9e9f a0a1  ................
        0x00b0:  a2a3 a4a5 a6a7 a8a9 aaab acad aeaf b0b1  ................
        0x00c0:  b2b3 b4b5 b6b7 b8b9 babb bcbd bebf c0c1  ................
        0x00d0:  c2c3 c4c5 c6c7 c8c9 cacb cccd cecf d0d1  ................
        0x00e0:  d2d3 d4d5 d6d7 d8d9 dadb dcdd dedf e0e1  ................
        0x00f0:  e2e3 e4e5 e6e7 e8e9 eaeb eced eeef f0f1  ................
        0x0100:  f2f3 f4f5 f6f7 f8f9 fafb fcfd feff 0001  ................
        0x0110:  0203 0405 0607 0809 0a0b 0c0d 0e0f 1011  ................
        0x0120:  1213 1415 1617 1819 1a1b 1c1d 1e1f 2021  ...............!
        0x0130:  2223 2425 2627 2829 2a2b 2c2d 2e2f 3031  "#$%&'()*+,-./01
        0x0140:  3233 3435 3637 3839 3a3b 3c3d 3e3f 4041  23456789:;<=>?@A
        0x0150:  4243 4445 4647 4849 4a4b 4c4d 4e4f 5051  BCDEFGHIJKLMNOPQ
        0x0160:  5253 5455 5657 5859 5a5b 5c5d 5e5f 6061  RSTUVWXYZ[\]^_`a
        0x0170:  6263 6465 6667 6869 6a6b 6c6d 6e6f 7071  bcdefghijklmnopq
        0x0180:  7273 7475 7677 7879 7a7b 7c7d 7e7f 8081  rstuvwxyz{|}~...
(etc.)


If I remove the "scrub" pf feature: There is no more problem.

-- 
You are receiving this mail because:
You are the assignee for the bug.